Yield response of continuous soybean to one-season crop disturbance in a previous continuous soybean field in Northeast China

Continuous soybean [Glycine max (L.) Merill.] may lead to yield decline due to its detrimental effect on soil health. Habitat disturbance affects numerous ecosystem components and processes. In this study, we assume the continuous soybean system as a normal tillage, any interference within the system is defined as a disturbance. Thus, crop disturbance is defined as a management practice used after a continuous soybean system to the seeding of the subsequent disturbed crop for one-season, and then switching to continuous soybean system. Six crops, grain soybean (Glycine max L. Merill.), wheat (Triticum aestivum L.), sugar beet (Beta vulgaris L.), tobacco (Nicotiana tabacum L.), corn (Zea mays L.), and hemp (Cannabis Satia L.) were seeded in a Mollisol farmland that had previously been cropped to continuous soybean for seven years, and then continuous soybean was implemented for three years. The soybean grain yield as a consequence of continuous soybean was significantly improved after hemp disturbance in the first and second year and after hemp and corn disturbance in the third year. The positive effect in hemp disturbance on succeeding soybean seed yield was 9.1-10.8% greater than that of continuous soybean. Increases in plant height, number of productive pod and seed number per plant as well as photosynthetic rates at R3 and R5 stage were responsible for the yield improvement of continuous soybean after hemp and corn disturbance. The attempt to increase yield of continuous soybean through the crop disturbance was considered successful. Adoption of hemp disturbance can be an alternative approach to managing continuous soybean production system. (C) 2012 Elsevier B.V. All rights reserved.